The Identification
of Ozone Exposures that Result in Vegetation Injury and Growth
Loss for Specific Species Grown in the Southern Appalachian Mountains

Concern about surface ozone effects on vegetation occurs
in many parts of the United States. Most of the available information
concerning the effects of ozone on vegetation is the result of
experimental exposure-response studies of important agricultural
crops and some selected forest tree species, usually seedlings.
Some ozone exposures (i.e., concentration applied over time)
result in visible foliar injury to the plant without growth reduction;
other exposures result in growth reduction and decrease in productivity
without visible injury, whereas some exposures result in both.

For assessing possible vegetation effects, A.S.L. &
Associates has

Described
ways in which ozone
exposures to vegetation
have been summarized for field and controlled studies and recommended biologically relevant exposure statistics
athat re the most important in describing a biological response;

Compiled and examined
the information from several sources and reviewed the articles
published;

Developed
either exposure-response
curves or summary
tables describing the relationship between the ozone exposure
and a specific biological endpoint (i.e., injury or damage);

Compared
ozone levels illustrated in the response curves with ambient
ozone levels observed across the region
of interest for the
period 1990-1995; and

Described
ways in which "scientifically defensible" atmospheric
modeling results for ozone can be integrated with the results from this study.